Dec. 12 (Bloomberg) -- An Asiana Airlines Inc. captain
nervous about making a visual landing in San Francisco
inadvertently disabled a speed-control system before the plane
crashed into a seawall on July 6, documents show.

Lee Kang Kuk, a veteran with Seoul-based Asiana who was
being trained on the Boeing Co. 777-200ER wide-body, had
momentarily adjusted the power without realizing the plane’s
computers then assumed he wanted the engines to remain at idle,
according to information released yesterday at a U.S. National
Transportation Safety Board hearing.

The documents, while showing the pilots made mistakes,
raise questions about the design of auto-throttles on Boeing
aircraft and whether related training has been adequate. The
safety board hasn’t concluded what caused the crash, which
killed three teenage girls from China in the first accident in
the U.S. with passenger deaths since 2009.

Lee, 45, “believed the auto-throttle should have come out
of the idle position to prevent the airplane going below the
minimum speed” for landing, the NTSB said in a summary of an
interview with him. “That was the theory at least, as he
understood it.”

In most modes of operation, the speed-protection system on
the 777 and several other Boeing aircraft won’t allow planes to
slow too much, safeguarding against accidents such as the Asiana
crash. The plane, on the verge of losing lift because it was
almost 40 miles (64 kilometers) per hour slower than its target
speed, broke apart after hitting the ground.

Cockpit Confusion

Asiana shares fell 0.1 percent to close at 4,795 won in
Seoul today. The stock has dropped 6.3 percent since the crash,
compared with a 7.3 percent gain in the benchmark Kospi index.

“The accident has damaged Asiana’s reputation especially
in China, one of its biggest markets,” said Kang Dong Jin, an
analyst at HMC Investment Securities Co. in Seoul. “It’s also
going to be a long-term financial burden because the outcome
could mean lawsuits and higher insurance payments.”

In some combinations of auto-throttle and autopilot
settings, such as during Asiana Flight 214’s approach to San
Francisco, the system becomes dormant, according to NTSB
documents.

The three pilots in the cockpit didn’t sense the impending
danger until seconds before impact, according to NTSB documents
and a voice-recorder transcript made public at the start of the
hearing.

Falling Fast

Bong Dong Won, 40, a crew member on board to give the
pilots a rest break, said at least twice that the plane was
descending too quickly in the final minute, according to the
transcript.

Lee and Lee Jung Min, 49, an instructor pilot monitoring
the captain as part of his training on the 777, failed to abort
the landing after the plane descended below 500 feet (152
meters), as was required under airline rules, according to the
documents.

“Asiana is committed to taking necessary steps to ensure
such an accident never happens again,” the airline said
yesterday in a statement responding to the NTSB hearing.

No one in the cockpit commented immediately after a series
of chimes 11 seconds before impact indicated that the plane had
reached dangerously low speed, according to the transcript.

Late Power

Shortly after the plane descended below 50 feet, the
plane’s control column began shaking to warn pilots they were in
danger of losing lift, known as an aerodynamic stall, according
to the recording.

Only then, 8.5 seconds after the initial speed warning, did
Lee Jung Min call for aborting the landing and climbing,
according to the transcript.

“Go around,” he said, after uttering an expletive in
English. The pilots added power too late to prevent the
collision.

Lee Kang Kuk, asked about his approach to the airport, told
safety-board investigators it “was very stressful, very
difficult.” He wasn’t accustomed to landing without an
instrument-landing system guiding him to the runway, as pilots
had to do in San Francisco that day because of airport
construction, according to an NTSB summary of his statement.

The captains still work for Asiana though they are not
flying, Ki Won Suh, an Asiana spokesman, said in an e-mail.
Bong, the relief pilot on Flight 214, has resumed flying.

Asiana since the accident has increased the hours of
flight-simulation training its pilots receive and taken other
steps to make a “fundamental improvement” in safety, Akiyoshi
Yamamura, senior executive vice president of safety and security
management, said Dec. 3.

Uncomfortable Pilots

Two former Asiana pilots said in interviews that most of
the carrier’s crews were uncomfortable with manual flight
maneuvers, according to NTSB documents. The pilots gave a
similar account in interviews with Bloomberg News in July.

A Federal Aviation Administration study released last month
found that pilots’ growing reliance on automation in the cockpit
has led to occasional confusion and new safety risks.

Autopilots, automatic throttles and computerized navigation
systems have helped improve safety in recent decades, the FAA
study concluded. The price for that is occasional confusion
because the systems, which sometimes interact with each other,
may be improperly set or act in ways that crews don’t
anticipate, it said.

“Obviously that’s an issue of great interest to the NTSB
as well as the entire aviation community,” NTSB Chairman
Deborah Hersman said at a press conference.

Autopilot Reliability

The devices are so reliable that pilots tend to assume
systems like speed control always work, Captain Dave McKenney,
of the International Federation of Air Line Pilots Associations,
said in testimony yesterday.

“When it doesn’t, they get caught short,” McKenney said.
McKenney was a co-author of the FAA study.

As Flight 214 from Seoul neared San Francisco, Lee Kang
Kuk, the training pilot, entered a series of parameters into the
flight-management and auto-throttle systems that made the plane
think he wanted to accelerate and climb.

To counter the plane’s increase in thrust, he pulled the
power back so he could resume his descent, the documents show.

Because of the way the auto-throttle had been set, combined
with the fact that he had shut off the autopilot, the throttles
stayed in the lowest setting, according to the NTSB.

Crash Landing

The impact sheared off the tail section and engines,
according to the NTSB. Besides the three passengers who died,
more than 200 people were taken to hospitals. The plane held 291
passengers, 12 flight attendants and four pilots.

All three victims may have been flung from the plane,
according to statements of unidentified witnesses who were
traveling with them, the NTSB said. At least one girl wasn’t
wearing her seatbelt, a student seated nearby said.

A 16-year-old girl traveling with a school group from China
was run over twice, not once, by fire trucks responding to the
crash, investigators disclosed at the hearing.

An autopsy found that the girl, who wasn’t named by the
NTSB, wasn’t dead until she was struck by a fire truck. She was
covered in firefighting foam. While investigators after the
accident said she was run over once, a review of video found a
second truck ran over her 11 minutes later.

Fire Department

“While we definitely regret the additional insult to the
deceased, this is not a matter of us being callous or careless,
either one,” said Dale Carnes, assistant deputy chief of the
San Francisco Fire Department.

Carnes described a chaotic post-crash scene at which
firefighters had to extinguish a blaze while freeing trapped
flight attendants and evaluating the injured.

Hersman of the NTSB, speaking in her opening statement to
families of the dead and those who were injured, said “nothing
can replace the loss of your loved ones or repair the trauma of
a life-changing injury.”

“But we do have the opportunity today to ensure that the
lessons of this tragedy are well learned and that the
circumstances are not repeated,” she said.